Dr. John Sharp, The University of Texas at Austin
Friday, February 12, 11 am, CSS 2324
“Deep and Wide: Implications from Studies of Carbonate Systems in Mexico”
Abstract: Cuatrociénegas and Zacatón are important karstic systems in Mexico. Cuatrociénegas is a world famous environmental system threatened by economic development. Its springs harbor a unique biotic assemblage. Our findings show that the springs are fed by a large, interbasin karstic system that that is still poorly understood, but that management will require a regional approach. Zacatón is formed by hypogene processes associated with Pleistocene volcanism that deposited extensive travertines and formed large phreatic cenotes (pozas). One of the pozas, El Zacatón, is perhaps the world’s deepest phreatic shaft that was mapped to ~317 meters depth by the DEPTHX robot. Calcite “lids”, detected by electrical resistivity, isolate large underlying water-filled voids. The recognition of analogous systems in Turkey and Australia implies that this volcanogenic (hypogene) karstification is not unique. Analyses of deep karstic systems may have to extend wider and deeper than is common for both scientific analyses and water resources management.